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• Interesting behavior in Media Source Extensions

  28 mai 2020, par newtonian_fig

  I'm trying to build a fairly standard video player using Media Source Extensions ; however, I want the user to be able to control when the player moves on to a new video segment. For example, we might see the following behavior :

  



  

  1. Video player plays 1st segment

  


  2. Source Buffer runs out of data causing the video to appear paused

  


  3. When the user is ready, they click a button that adds the 2nd segment to the Source Buffer

  


  4. The video continues by playing the 2nd segment

  


  



  This works well, except that when the video appears paused during step 2 it doesn't stop at the last frame of the 1st segment. Instead, it stops two frames before the end of the 1st segment. Those last two frames aren't being dropped, they just get played after the user clicks the button to advance the video. This is an issue for my application, and I'm trying to figure out a way to make sure all of the frames from the 1st segment get played before the end of step 2.

  



  I suspect that these last two frames are getting held up in the video decoder buffer. Especially since calling endOfStream() on my Media Source after adding the 1st segment to the Source Buffer causes the 1st segment to play all the way through with no frames left behind.

  



  Additional Info

  



  

  • I created each video segment file from a series of PNGs using the following ffmpeg command

  


  



  ffmpeg -i %04d.png -movflags frag_keyframe+empty_moov+default_base_moof video_segment.mp4

  



  

  • Maybe this is a clue ? End of stream situations not handled correctly (last frames are dropped)

  


  • Another interesting thing to note is that if the video only has 2 frames or less, MSE doesn't play it at all.

  


  • The browser I'm using is Chrome. The code for my MSE player is just taken from the Google Developers example, but I'll post it here for completeness. This code only covers up to step 2 since that's where the issue is.

  


  



  <code class="echappe-js">&lt;script&gt;&amp;#xA;const mediaSource = new MediaSource();&amp;#xA;video.src = URL.createObjectURL(mediaSource);&amp;#xA;mediaSource.addEventListener(&amp;#x27;sourceopen&amp;#x27;, sourceOpen, { once: true });&amp;#xA;&amp;#xA;function sourceOpen() {&amp;#xA;  URL.revokeObjectURL(video.src);&amp;#xA;  const sourceBuffer = mediaSource.addSourceBuffer(&amp;#x27;video/mp4; codecs=&quot;avc1.64001f&quot;&amp;#x27;);&amp;#xA;  sourceBuffer.mode = &amp;#x27;sequence&amp;#x27;;&amp;#xA;&amp;#xA;  // Fetch the video and add it to the Source Buffer&amp;#xA;  fetch(&amp;#x27;https://s3.amazonaws.com/bucket_name/video_file.mp4&amp;#x27;)&amp;#xA;  .then(response =&gt; response.arrayBuffer())&amp;#xA;  .then(data =&gt; sourceBuffer.appendBuffer(data));&amp;#xA;}&amp;#xA;&amp;#xA;&lt;/code&gt;&lt;/pre&gt;&amp;#xA;

• How to generate an MP4 for use with Media Source Extensions using ffmpeg ?

  21 novembre 2014, par Pablo Montilla

  I’m using ffmpeg to generate a fragmented mp4 stream that will be consumed by an HTML5 player using MSE. I think I have a correctly formatted mp4 stream of data with an empty moov at the start and a series of moof+mdat for the video fragments. What I’m stuck is with the codec that’s being received by Chrome.

  chrome ://media-internals has this to say :

  00:00:00 00 pipeline_state  kCreated
  
  00:00:00 00 EVENT           PIPELINE_CREATED
  
  00:00:00 00 EVENT           WEBMEDIAPLAYER_CREATED
  
  00:00:00 00 url             blob:http%3A//localhost/3388b7f1-5567-4d76-a585-0b247affd16a
  
  00:00:00 00 pipeline_state  kInitDemuxer
  
  00:00:07 68 error           Video codec: avc1.4d401e

  From which I gather the problem is with the encoded data, which should be in avc1.4d0020 as its specified in the javascript.

  I’ve seen the answer to html5 video tag codecs attribute, which tells me I need to reset profile_compatibility and AVCLevelIndication, but I couldn’t find an option to do that.

  Here’s the command line I’m using (the pipe is read and sent to the web page using web sockets) :

  ffmpeg -re -i Input.mp4 -map 0:0 -y -c:v libx264 -preset veryslow -x264opts intra-refresh=1 -tune psnr -refs 1 -b:v 1500k -bf 0 -g 8 -b-pyramid none -f mp4 -movflags empty_moov+omit_tfhd_offset+frag_keyframe -frag_duration 1000000 -profile:v main -iods_video_profile 0 -flags +loop \\.\pipe\FeedPipe

• Vitamio Media Player License Requirements

  27 mai 2015, par Amanda Fernandez

  I have successfully integrated vitamio project in my app and it works perfectly. But I’m not clear about its licence. I found the project in github. It uses ffmpeg library and some of the files have apache license. So can I use, vitamio for enterprise app without the license ? Or license is mandatory. ?